Benneteau managed what no other player at the tournament achieved — breaking Del Potro's service twice in the first set — but always struggled to hold his own service against the big-hitting Argentine and crumbled in the second set.

The 2009 U.S. Open winner had not dropped a service game heading into the final. He lost last year's final to Roger Federer.

Benneteau, who ended the No. 2-ranked Federer's quest to defend his title in the quarterfinals, is now 0-8 in ATP finals.

"We are getting closer and closer. I am sure with you I can win a title," Benneteau said as he thanked his coach, Loic Courteau.

Benneteau saved four match points when serving at 5-2 in the second set, but it was only a stay of execution as Del Potro served out the match to love.

While Benneteau managed to break the 1.98-meter (6-foot-6) 2nd-seeded Argentine, Del Potro hit back immediately, breaking Benneteau as he reeled off four straight games to take command of the opening set.

Benneteau saved two set points on his own serve at 5-3 and then broke Del Potro a second time on his way to forcing the set to a tiebreak. But the experienced Argentine dominated to take the set.

Possibly still feeling the effects of his Benneteau seemed sluggish in the second set as Del Potro ran away with the match, serving the final game with wadding in one nostril after suffering a nose bleed.